Removable segment, track-mounted terminal block



Feb. 22, 1966 w. A. DE SMIDT ETAL 3,236,975

REMOVABLE SEGMENT, TRACK-MOUNTED TERMINAL BLOCK 4 Sheets-Sheet 1 Filed Nov. 24, 1961 INVENTORS WOODROW A- DE SMDT DONALD V. ECKMAN ATTORNEY Feb. 22, 1966 w. A, DE SMIDT ETAL 3,236,975

REMOVABLE SEGMENT, TRACK-MOUNTED TERMINAL BLOCK Filed Nov. 24

WOODROW A.DE SMIDT DONALD V. ECKMAN BY QZZZ ATTORNEY Feb. 22, 1966 w. A. DE SMIDT ETAL 3,236,975

REMOVABLE SEGMENT, TRACKMOUNTED TERMINAL BLOCK Filed Nov. 24, 1961 4 Sheets-Sheet 5 INVENTORS WOODROW A.DE SMIDT DONALD V. ECKMAN ATTORNEY Feb. 22, 1966 w. A. DE SMIDT ET AL 3,236,975

REMOVABLE SEGMENT, TRACKMOUNTED TERMINAL BLOCK 4 Sheets-Sheet 4 Filed Nov. 24, 1961 S R O T N E V N WOODROW A.DE SMIDT DONALD V. ECKMAN dfl fi M ATTORNEY United States Patent 0 3,236,975 REMOVABLE SEGMENT, TRACK-MOUNTED TEINAL BLOCK Woodrow A. De Smidt, Whitefish Bay, and Donald V. Eckman, Milwaukee, Wis.., assignors to Allen-Bradley Company, Milwaukee, Wis, a corporation of Wisconsin Filed Nov. 24, 1961, Ser. No. 154,547 8 Claims. (til. 260-133) This invention relates to a terminal block for the wiring of circiuts, and it more specifically resides in a terminal block that is assembled from a number of terminal bearing segments individually mounted upon a channel shaped track having upright flanges terminating in horizontal rails, such segments including a base which lies betwen the flanges and cooperates with a pair of slender legs emanating from the base which lie to the outside of the rails to grip the track until released by flexing the legs.

Terminal blocks are commonly employed in electrical panels, and other circuit wiring, to provide a series of spaced terminals that facilitate wiring and provide convenient means for connection with external apparatus. Some of these terminal blocks are formed of modular segments that can be combined to obtain the exact number of terminals required for the specific circuit. It is desirable that such terminal blocks be assembled from non-interlocking segments which are individually mounted upon a common track so that the terminal block may be easily serviced or altered once it has been assembled and installed. However, it is necessary that the mounting of such non-interlocking segments be accomplished in such a manner that accidental dislodging of the segments is prevented. To this end, each segment of the terminal block of this invention surrounds and engages a mounting track whereby a positive action with a prying tool is required to release the segment from its mounting.

Secure mounting of the segments is accomplished through the use of a channel shaped mounting track which includes a central horizontal web provided with a pair of upright flanges each terminating in an outwardly extending rail, in combination with segments provided with a base which extends between and engages the inner surfaces of the flanges and top surfaces of the rails, and depending slender legs which lie to the outside of the track to engage the underside and outer edges of the rails. Mounting and removal of the segments may be accomplished only by the use of a prying tool to flex the slender legs sufficiently to clear the outer edges of the rails. Provision is made in the segments to accommodate a prying tool.

Since it is not always possible at the time of manufacture of a terminal block to anticipate the number of seg ments which will be needed in any particular installation, the block of this invention is adapted to be supplied in long lengths from which specific blocks may be separated. For this purpose, the track is notched at spaced intervals along its length to provide points of reduced cross section, whereby a desired length of block may be formed by physically breaking the track at these points of reduced cross section. This allows the user of the terminal block to tailor the block to his specific individual needs.

A particular feature of the terminal block resides in the provision for mounting the block at any of a plurality of points along its length. To accomplish this, the web of the mounting track is provided with a series of holes spaced throughout its length to receive headed mounting members, and the base of each segment is formed to accommodate such mounting members.

Since the individual segments are not interlocked, it is desirable to provide retaining means to prevent longitudinal movement of the segments along the mounting track. End brackets are employed for this function which removably engage the inner surfaces of the flanges of the track and which bear against the endmost segment. The securing of such end brackets is accomplished without resort to external means such as screws, and each bracket is formed to provide clearance for the headed mounting members.

Multiple segment terminal blocks as heretofore used have been generally limited to the mounting of terminal conductors. The segments forming the block of this invention are not so limited, but rather can be varied in form for mounting other types of circuit elements. For example, fuses may be incorporated in a terminal block of the present invention. The portions of the segments that engage the mounting track remain the same for all segments, and a uniformity for the assembly of the segments is retained regardless of the form of circuit element being mounted.

It is, therefore, an object of this invention to provide a terminal block comprised of a plurality of track mounted segments which are releasable for disassembly or alteration of the terminal block by use of a prying tool.

It is a further object of this invention to provide a terminal block comprised of a plurality of track mounted segments restrained longitudinally by removable end brackets which engage the track.

It is another object of this invention to provide a terminal block which may be mounted at a plurality of positions along its length by headed members which are accommodated by track mounted segments of the block and restraining end brackets.

It is still another object of this invention to provide a track mounted terminal block capable of mounting various types of terminals and other circuit elements.

It is also an object of this invention to provide a terminal block which may be tailored by users to particular specifications.

The foregoing and other objects and advantages of this invention will appear from the following description. In the description reference is made to the accompanying drawings, which form a part hereof, and in which there is shown by way of illustration, and not of limitation, specific forms in which this invention may be embodied.

In the drawings:

FIG. 1 is a view in elevation of the terminal block of this invention with a portion thereof broken away,

FIG. 2 is a view in elevation of the terminal block viewed from the left end of FIG. 1,

FIG. 3 is a view in elevation of the terminal block viewed from the right end of FIG. 1,

FIG. 4 is a plan view of the terminal block of FIG. 1,

FIG. 5 is a bottom view of the terminal block of FIG. 1,

FIG. 6 is a front view in elevation of one type of segment used in the terminal block,

FIG. 7 is a side view of the segment of FIG. 6,

FIG. 8 is a rear view in elevation of the segment of FIG. 6,

FIG. 9 is an exploded view in perspective of a second type of segment used on the terminal block together with an associated terminal conductor and marking indicia strip,

FIG. 10 is an exploded view in perspective of another type of terminal conductor adapted to be borne by the segment of FIG. 9,

FIG. 11 is a view in perspective of still another type of terminal conductor adapted to be borne by the segment of FIG. 9,

FIG. 12 is an exploded view in perspective of a terminal block and end bracket of the invention that shows the method of removal of individual segments,

FIG. 13 is a view in perspective of a third type of segment used on the terminal block which mounts a fuse assembly, and

" FIG. 14 is a view in section taken in the plane of the bly segment 4.

Each of the segments is formed of suitable insulating material such as molded nylon that is relatively stiff. The segments 2, 3 and 4 may be arranged upon the track 1 in any desired sequence, and they are shown arranged in an orderly progression in FIGS. 1 through merely for purposes of illustration. The segments 2, 3 and 4 are restrained from longitudinal movement upon the track 1 by end brackets 5 which abut against each end segment of the series of segments 2, 3 and 4.

The channel-like track 1 includes a pair of flanges 6 each of which terminates in an outwardly bent, horizontally extending rail 7. The track 1 is provided with a series of slots 8 which extend through each rail 7 and further extend into the upper portion of the associated flange 6. The slots 8 are preferably spaced along the entire length of the track 1 at a distance equal to one-half of the width of the smaller terminal conductor segment 2. A center web 9 of the track 1 has its lower surface scored with a plurality of transversely extending notches 10 which are in alignment with the series of slots 8 and which extend partially through the depth of the center web 9. The slots 8 and aligned notches 10 thereby provide a plurality of points of reduced cross section of the track 1. A series of oblong mounting holes 11 are provided in the web 9 of the track 1. Each hole 11 is preferably positioned centrally of two adjacent notches 10 and extends longitudinally to encompass such adjacent notches 10 so that the smallest cross section of the track 1 will be provided at the position of the notches 10 and aligned slots 8 (see FIG. 5).

Referring particularly to FIGS. 6-8, each larger terminal conductor segment 3 has a base designated generally by the reference numeral 12 which includes a pair of downwardly extending slender legs 13 which straddle a trunk 14 that merges with the legs 13 at their respective upper extremities. The front surface of the base 12 lies in a single plane to define a front face 15 of the segment 3. The trunk 14 includes a pair of downwardly extending fingers 16 each spaced inwardly from respective lateral sides of the trunk 14 to define a pair of abutment surfaces 17 at the bottom of the trunk 14. Each leg 13 terminates at its lower extremity in a foot 18 which includes a toe 19 that extends inwardly from the interior surface of the foot 18 and an upwardly bent heel 20 that extends outwardly from the foot 18. An upper surface of the base 12 provides a seat portion 21 for positioning a terminal conductor thereon, as will hereinafter be described.

An insulating partition rib 22 rises upwardly from the base 12 and is positioned relative thereto so that the rear faces of the insulating rib 22, and the base 12 lie in a common plane to define a back face 23 of the segment 3. The rib 22 has a transverse width greater than the width of the base 12. A generally rectangular boss 24 projects forward from the rib 22 and is positioned so that its upper surface 25 lies below the upper edge of the rib 22. The boss 24 is preferably hollow to conserve material and reduce the weight of the segment 3. The upper edge of the rib 22 is provided with a marking indicia notch 26 which extends downwardly to form a continuation of the upper surface 25 of the boss 24 and which defines a pair of restraining lugs 27. The boss 24 projects from the rib 22 a sufficient distance so that its front surface lies in the same plane as the front face 15. Projecting outwardly from the front surface of the rib 22 is a shoulder 28 which is positioned between the seat portion 21 and a bottom surface 29 of the boss 24. The depth of the shoulder 28 is governed by the dimensions of the terminal conductor to be carried by the segment 3. A positioning pin 38 also projects outwardly from the rib 22 and is disposed between the seat portion 21 and bottom surface 29 of the boss 24.

The base 12 is further provided with a pair of holes 31 which extend from the front face 15 to a point short of the plane defined by the front surface of the rib 22. A pair of detents 32 are provided in the back face 23 of the segment 3 in line with the holes 31. The base 12 may also be provided with a recess to conserve material and reduce weight (see FIG. 6).

A suitable terminal conductor 33, such as one having a capacity of 50 amperes, is borne by each segment 3. The terminal conductor 33 shown in FIGS. 1-5 is comprised of a box-like bus bar 34 having open ends to receive a pair of terminal fixtures 35 each held in place by a terminal screw 36 threaded in a hole provided in the top surface of the bus bar 34 and adopted to bias against the terminal fixture 35 to clinch an electrical lead inserted between the terminal fixture 35 and the interior of the bus bar 34. One side wall of the bus bar 34 is provided with a centrally positioned opening 37, so that the terminal conductor 33 is received between the seat portion 21 and bottom surface 29 of the boss 24 with the positioning pin 30 received within the opening 37. The pin 38 prevents transverse movement of the terminal conductor 33, and the shoulder 28 is of sufiicient depth so that the conductor 33 will be restrained from longitudinal movement when the segments are placed in series by the presence of the back face of an adjacent segment or of a closure member as will hereinafter be described.

Each segment 3 is held upon the mounting track 1 by gripping each rail 7 between a leg 13 and the adjacent portions of the trunk 14 and its fingers 16. Thus, the outer edge and lower surface of each rail 7 is engaged by a toe 19 of a foot 18, while the upper surface of each rail 7 is engaged by an abutment surface 17 of the trunk 14 and the fingers 16 engage the inner surfaces of the flanges 6.

Referring now to the segments 2, they are adapted to receive various types of terminal conductors of a current capacity less than the terminal conductors 33, for example they may have a rating of 25 amperes. The base of each of the segments 2 is similar in construction to the base 12 of the segments 3. Thus, a base designated generally by the numeral 38 includes a pair of slender legs 39 held in spaced relation and merged at their upper extremities with a trunk 40 which has a pair of downwardly extending fingers 41 and a pair of abutment surfaces 42. Each leg 39 has a foot 43 which includes an inwardly extending toe 44 and an outwardly extending heel 45 (see FIG. 9). An upper surface of the base 38 forms a seat portion 46. An insulating partition rib 47 extends upwardly from the base 38 and has its rear face lying in the same plane as the rear face of the base 38 to define a back face 48 of the segment 2. A box-like boss 49 projects from the rib 47 with its upper surface 50 slightly below the top edge of the rib 47 to thereby define a marking indicia notch 51. Restraining lugs 52 project from each side of the notch 51.

Each segment 2 also includes a positioning pin 53 extending from the rib 47 and disposed between the seat portion 46 and a bottom surface 54 of the boss 49. A pair of holes 55 are provided in the base 38 extending from the front face 56 of the base 38 to a point short of the plane defined by the front surface of the rib 47. The back face 48 is provided with a pair of detents 57 in alignment with the holes 55, and as is apparent from the drawings each segment 2 is mounted on and grips the track 1 in the same manner as the segments 3 engage the track 1.

The segments 2 are adapted to receive various types of terminal conductors, as are illustrated in FIGS. 911. Referring first to FIG. 9, a bus bar type terminal conductor 58 is shown that comprises a box-like bus bar 59 having a pair of terminal screws 60 threadedly received in holes provided in the top wall of the bus bar 59. The screws 60 bias against respective ends of a terminal fixture 61 disposed longitudinally within the bus bar 59, so that the terminal conductor 58 is adapted to grip electrical leads between the terminal fixture 61 and the lower Wall of the bus bar 59. The terminal conductor 58 is borne by a segment 2 between the seat portion 46 and the bottom surface 54 of the boss 49, and is restrained from transverse movement by the positioning pin 53 which is received within a suitable opening 61 provided in a side wall of the bus bar 59.

A clip type terminal conductor 63 as shown in FIG. 10 may also be borne by a segment 2. The terminal conductor 63 is comprised of a notched conductor member 64 which is adapted to receive a clip fitted electrical lead 65 at each transversely extending end. The conductor member 64 is provided with extensions 66 which are received within cooperating slots 67 provided in the top and bottom arms of a U-shaped yoke 68. The terminal conductor 63 is held by the segment 2 between the seat portion 46 and the bottom surface 54 of the boss 49, and is prevented from moving transversely by the positioning pin 53 which is received within an opening 69 provide in the conductor member 64.

The segment 2 may also receive a terminal screw type terminal conductor 70, as shown in FIG. 11, comprised of a generally T-shaped member 71 having its cross bar 72 provided centrally with a seating surface 73. A pair of terminal screws 74 are received in threaded holes provided at each end of the cross bar 72 for making connection with circuit leads. The segment 2 receives the terminal conductor between the seat portion 46 and boss 49 whereby the bottom of a stem 75 of the T-shaped mem ber 71 rests upon the seat portion 46 and the seating sur face 73 of the cross bar 72 engages the bottom surface 54 of the boss 49. An opening '76 is provided in the stem 75 to receive the positioning pin 53.

It is to be understood that the terminal conductors which may be borne by the segment 2 are not limited to the types above described, and that a similar variety of conductors can be mounted in the larger segments 3. Any type terminal conductor or circuit element which may be adapted to fit between the seat portion 46 and the boss 49 and which may be provided with an opening to receive the pin 53 may be employed.

The terminal block segment 4, which is adapted to carry a fuse assembly, has a base similar to those of segments 2 and 3. Thus, a base 77 includes a pair of slender legs 78 which are held in spaced relation and are connected at their upper extremities to a trunk 79 disposed between the legs 78 (see FIG. 13). The trunk 79 is provided with a pair of fingers 80 which project downwardly and with a pair of abutment surfaces 81. Each leg 78 terminates in a foot 82 having an inwardly extending toe 83 and an outwardly extending heel 84. A suitable insulating partition rib 85 extends upwardly from the base 77 and is provided at its upper edge with a marking indicia notch 86 which defines a pair of restraining lugs 87 projecting from the rib 85. A back face 88 of the segment 4 is defined by a plane common to the rear faces of the rib 85 and the base 77, and a front face 89 is defined by the front surface of the base 77. The base 77 is provided with a pair of holes 90 which extend from the front face 89 to a point short of the plane defined by the front surface of the rib 85. A pair of detents 91 are provided in the back face 88 in alignment with the holes 90. The segment 4 engages the track 1 in the same manner as the segments 2 and 3.

The rib 85 is provided with a fuse assembly mounting boss 92 which projects outwardly from the front surface of the rib 85. The fuse assembly includes an upper L shaped conductor member 93 and a lower L-shaped conductor member 94. The upper conductor member 93 is aflixed to an upper portion of the mounting boss 92 by a screw 95 which extends through the boss 92 into a threaded hole provided in an arm 96 of the conductor member 93. An upper fuse clip 97 is attached to the arm 96 by a screw 98. A second arm 99 of the upper conductor member 93 is notched to receive a terminal fixture 180 which surrounds the arm 99, and which is held in place by a terminal screw 181. The lower conductor member 94 is aifixed to a lower portion of the boss 92 by a screw 102 which extends through the boss 92 into engagement with a threaded hole provided in one arm 103 of the conductor member 94. A lower fuse clip 184 is aflixed to the arm 103 by a screw 105. A second arm 196 of the lower conductor member 94 rests upon a seat portion 197 defined by an upper surface of the base 77 and is notched to receive a terminal fixture 1118 held in place by a terminal screw 189. Electrical leads may be gripped between the terminal fixtures and 188 and the associated arms 99 and 106, respectively. A fuse is held by the fuse clips 97 and 104. The adjacent ends of the arms 96 and 183 are separated by an insulating portion 111 which projects from a side of the boss 92. A ledge 112 is provided as an extension of one leg '7 8.

The small end brackets 5 are adapted to engage the track 1 to prevent longitudinal movement of an assembly of segments 2, 3 and 4 mounted upon the track 1. Each bracket 5, as shown in FIG. 12, is formed of a stamping suitably bent to provide a web section 113 and an upright retaining strip 114 having a pair of bearing surfaces 115 and spaced tabs 116. The web section 113 is formed with a vaulted central portion 117 which terminates on either side in serrated edges 118. The serrations on the edges 118 are directed toward the upright retaining strip 114.

The legs 13 of the segments 3 are relatively long and narrow in vertical cross section and connect with the trunk 14 at points substantially above the track gripping feet 18 and cooperating fingers 16. Such construction imparts a limited degree of flexibility to the legs 13 although the segment 3 is formed of a stiff insulating material. Since the bases 38, 12 and 77 of the segments 2, 3 and 4, respectively, are identical in form and construction and vary only in depth, the legs 39 and 78 are similarly provided with a limited degree of flexibility. Suitable flexibility may be obtained by providing each leg 13, 39 and 78 with a length three times the width thereof.

In assembling a terminal block from a plurality of segments 2, 3, 4 the segments may he slipped onto the track 1 from one end of the track, but in the alternative each of the segments 2, 3 and 4 may be individually mounted on upon the track 1 in the method to be described. For brevity, the method will be described with reference to a segment 3, it being understood that the segments 2 and 4 are mountable in similar manner. The method consists of initially hooking the toe 19 of one leg 13 under an adjacent rail 7 of the track 1. The second leg 13 is then flexed outwardly to permit the toe 19 of the second leg 13 to clear the outer edge of its adjacent rail 7, thereby allowing the segment 3 to move downward into place. The legs 13 will move toward each other after the rail 7 has been cleared, and will thereby grip the track 1 to secure the segment 3 thereto. This method of'mounting is particularly useful for altering blocks previously assembled, or for mounting in restricted areas where the track 1 is already placed upon a panel. Removal of a segment 3 from the track 1 is similarly accomplished by flexing one of the legs 13 outwardly until its toe 19 clears the outer edge of the adjacent rail 7.

Since the legs 13 are provided with only a limited degree of flexibility by reason of their construction, it is very diflicult to exert by hand suflicient force on the legs 13 to clear the rails 7. Therefore, it is necessary to em ploy a suitable prying tool such as a screwdriver when mounting or removing a segment 3 from the track 1. Referring to FIG. 12, the end of a screwdriver is placed between one leg 13 and its adjacent heel 26. This permits sufficient leverage to be exerted on the leg 13 to flex the same so that the toe 19 can clear the outer edge of the rail 7. Each of the segments 2, 3 and 4 also contains an integral portion which may be used as a fulcrum for the prying tool. Thus, the outwardly extending portions of the insulating ribs 47 and 22 act as fulcrums for the segments 2 and 3, respectively, and the ledge portion 112 acts as a fulcrum for the segment 4.

Each segment 2, 3 and 4 grips the track 1 in such a manner that a positive action is required to dislodge the segment thereby preventing the possibility of accidental removal of the segment. For example, each segment 4 is restrained against upward movement by the toes 83 engaging the underside of the rails 7 and downward movement is prevented by the abutment surfaces 81 which engage the top surfaces of the rails 7 (see FIG. 13). In addition, lateral movement of the segments 4 is prevented by each foot 82 engaging the outer edge of the rails 7 and each finger 80 engaging the inner surface of a flange 6. By gripping the track 1 in all directions and because of the limited flexibility of the legs 78, a positive action is required to dislodge the segments 4.

When the segments 2, 3 and 4 are mounted upon the track 1, a segment at one end of the series of segments Will have its front face 15, 56 or 89 respectively, facing outwardly. A suitable insulating closure member is provided for each segment to permit closure of each end of the series of segments. Referring to FIG. 3, an insulating closure member 119 is provided with a configuration similar to the insulating rib 35 of the segment 4. The closure member 119 is provided with a pair of holes so positioned that when the member 119 is placed against the front face 88 of the segment 4 the holes will be in alignment with the holes 90. The member 119 is secured to the segment 4 by a pair of self-tapping screws 120 extending through the holes provided in the member 119 and into the holes 90 of the segment 4. Insulating closure members are also provided for the segments 2 and 3 having configurations similar to the respective insulating ribs 22 and 47. Thus, a closure member 121 is adapted to be secured to the front face 56 of the segment 2 by a pair of self-tapping screws 122 (see FIG. 12). The closure members may also be provided with a depending base and slender legs to engage the track in the same manner is the segments 2, 3 and 4 (not shown).

Once the segments 2, 3 and 4 have been mounted upon the track 1, one end bracket 5 is used at each end of the series to prevent longitudinal movement of the segments. Referring to FIG. 12, the end brackets 5 are mounted on the track 1 by inserting the web section 113 between the flanges 6 and below the segments. The fingers 41, 16 and 80 of the segments 2, 3 and 4, respectively, terminate short of the center web 9 of the track 1 to provide clearance for the serrated edges 118 which engage the inner surfaces of the flanges 6. The bearing surfaces 115 of the upright restraining strip 114 abut against the end segment or closure member. The tabs 116 are provided to assist in removing the brackets 5. The vaulted central portion 117 is provided to clear a headed mounting member in the form of a screw 128 which may be received in the oblong holes 11 provided in the web 9 of the track 1 to mount the terminal block on a panel 129. The portion of each of the trunks 40, 14 and 79 8 which spans the respective fingers 41, 16 and rises to a height above the top surfaces of the rails 7 to receive thevaulted central portions 117 of the brackets 5 and to accommodate headed mounting members.

After the terminal block has been installed, individual segments may be added, substituted or eliminated as dictated by the requirements of the installation. As indicated above, each of the segments 2, 3 and 4 may be individually removed from the track 1 by the use of a suitable prying tool although accidental removal of the segments is prevented.

Additional segments 2, 3 and 4 may be added to either end of the series of segments merely by removing the brackets 5. It is not necessary to remove closure members affixed to the end segments. For example, a segment 2 may be added to the track 1 in side-to-side abutting relation to the segment 4 and its attached closure member 119, after removal of the adjacent bracket 5. The screws 120 will not interfere with the positioning of the segment 2 since the detents 57 provided in the back face 48 of the segment 2 receive the heads of the screws 120 thereby permitting face-to-face contact of the back face 48 with the outer surface of the closure member 119.

Each of the segments 2, 3 and 4 is adapted to receive marking indicia either singly or in strip form. Referring to FIG. 4, a labeling strip 123 is adapted to be received within the indicia notches 26 provided in the segments 3. The strip 123 is held in position on the upper surfaces 25 of the bosses 24 by the lugs 27. The labeling strip 123 is similarly adapted to be received within the notches 51 of the segments 2 where it is held in place by the lugs 52. The strip 123 has one surface 124 coated, as with paint, so that the surface 124 and an opposite surface 125 are of contrasting colors. Single labels 126 having contrasting surfaces 127 and 128 may be inserted in the notches 86 provided in the segments 4. Also, the strip 123 may be employed with the segment 4 and the single labels 126 may be used with the segments 2 and 3. By providing the labeling strip 123 and labels 126 with contrasting surfaces, the uncoated surfaces 125 and 128, respectively, may be written upon, whereas the coated surfaces 124 and 127, respectively, may be marked by removing the coating, as by scratching, to expose the contrasting base material (see FIG. 4).

In the preferred embodiment, the points of a reduced cross section of the track 1 are spaced at a distance equal to one-half of the depth of the segments 2. Also, the segment 3 preferably has a depth equal to the distance between three notches 10, so that a modular spacing between points of reduced cross section is provided. When the segments 2 and 3 are mounted upon the track 1, they are positioned with their respective faces in alignment with the slots 8 and notches 10. The terminal block may then be supplied in standard lengths and the individual user is able to tailor the block to his needs by physically breaking the track 1 at the points of reduced cross section.

It will be apparent from the above description that the terminal block of this invention may be tailored to meet individual needs by provision of non-interlocking segments individually mounted upon a common track which may be broken to desired lengths and which is gripped by end brackets which bear against the endmost segments. Additions, substitutions and repairs to the segments and terminals may be made Without completely disassembling the block. Each segment securely grips the track until released by means of a prying tool. The block may be mounted at a variety of points along its length.

We claim:

1. In a terminal block the combination comprising: a channel-shaped mounting track having spaced upwardly turned flanges that terminate in outwardly extending generally horizontal rails; and a plurality of individual segments of stiff insulating material removably mounted on said track and that are disposed in side-to-side abutting relation, each of said segments having a base with a trunk that extends downwardly between the flanges of said trunk and engages both the upper surfaces of the rails and the inner surfaces of the flanges, each base also having a pair of slender legs that lie to the outside of said flanges and are spaced from said trunk to define a vaulted space between each leg and said trunk with the top of said vaulted space at a level substantially above said rails to provide limited flexibility to said legs, each leg terminating at its lower extremity in a foot having an inwardly turned toe engaging the outer edge and bottom surface of an adjacent rail for grasping the rail, and each leg also having an upwardly bent heel extending outwardly from the track to present means for engagement by a tool to flex the leg away from said trunk for the removal of the segment from the track.

2. In a terminal block the combination comprising: a channel-shaped mounting track having a web and spaced upwardly turned flanges rising from each side of said web and that terminate in outwardly extending generally horizontal rails, a lower surface of said web being scored with a plurality of spaced transversely extending notches and said web being provided with a plurality of oblong mounting holes each of which encompasses an adjacent pair of said notches, and said rails and connecting flanges being provided With a plurality of slots in alignment with said notches whereby said slots, notches and oblong mounting holes provide a plurality of points of reduced cross section equally spaced co-extensive of the length of said track so that said track may be physically broken at any of said points of reduced cross section; and a plurality of individual segments of stiff insulating material removably mounted on said track that are disposed in side-to-side abutting relation, each segment having a base with a portion that extends downwardly between the flanges of said track and engages both the upper surfaces of the rails and the inner surfaces of the flanges, and also having a pair of spaced slender legs depending from said segment from a level substantially above said rails and that lie to the outside of said flanges, each leg terminating at its lower extremity in a foot having an inwardly turned toe engaging the outer edge and bottom surface of an adjacent rail and an upwardly bent heel extending outwardly from the track to present means for engagement by a tool to flex the leg for the removal of the segment from the track.

3. In a terminal block assembly the combination comprising: an elongated channel shaped mounting track having a central horizontal web, vertical flanges rising from each edge of the web which are spaced from one another, and horizontal rails turning outwardly from the upper edges of the flanges; a plurality of terminal block segments of stiff insulating material, each of said terminal block segments having a base portion that includes a central trunk with a pair of spaced depending fingers that parallel said flanges and fit snugly therebetween with vertical sides of said fingers that bear against the inside surfaces of the flanges, and said trunk also having downwardly facing horizontal abutment surfaces which extend sideward from each finger and bear upon the upper faces of said rails, said base portion also including a pair of downwardly extending slender legs that lie to the outside of the trunk and are spaced from said trunk to define a vaulted space between each leg and said trunk with the top of the vaulted space substantially above the level of said rails to provide limited flexibility to said legs, and each leg having a foot at its lower free end with a toe facing inwardly that presents a horizontal face engaging the underside of a rail and a vertical face engaging the outer edge of such rail; and a projection at the back of each foot adapted for engagement by a tool to flex the leg outwardly to disengage from or engage with a rail.

4. A terminal block in accordance with claim 2 wherein each of said segments has a depth equal to a whole multiple of the distance between said points of reduced cross section of said track.

5. In a terminal block assembly the combination comprising: an elongated channel shaped mounting track having a central horizontal web, vertical flanges rising from each edge of the web which are spaced from one another, and horizontal rails turning outwardly from the upper edges of the flanges; a plurality of terminal block segments of stiff insulating material each having a base with a pair of spaced depending fingers that parallel said flanges and fit snugly therebetween and bear against the inside surfaces of the flanges with the bottom of each finger spaced above the mounting track web, the part of the base spanning between said fingers rising to a height above said rails, and the base having downwardly facing abutment surfaces which extend sideward from each finger and bear upon the upper faces of said rails; said terminal block segments also having downward extending legs branching from the sides of the bases at a level substantially above said rails, each leg having a length at least three times the transverse thickness thereof to impart limited flexibility to the leg, and each leg having a foot at its lower free end with a toe facing inwardly that presents a face engaging the underside of a rail and a face engaging the outer edge of such rail; a projection at the back of each foot adapted to engagement by a tool to flex the leg outward to disengage from or engage with a rail; and end brackets for the terminal block segments and removably mounted on said track, each end bracket having an upright strip bearing against the end face of an endmost segment, and a web section that fits between the rails and extends beneath the fingers of the adjacent segment.

6. In a terminal block assembly the combination comprising: an elongated channel shaped mounting track having a central horizontal web, vertical flanges rising from each edge of the web which are spaced from one another, and horizontal rails turning outwardly from the upper edges of the flanges; a plurality of terminal block segments of insulating material removably mounted on said track, each of said segments having a base with a pair of spaced depending fingers that parallel said flanges and fit snugly therebetween and bear against the inside surfaces of the flanges with the bottom of each finger spaced above the mounting track web, the part of the base spanning between said ribs rising to a height above said rails, and the base having downwardly facing abutment surfaces which extend sideward from each rib and bear upon the upper faces of said rails; said terminal block segments also having downward extending slender legs having limited flexibility and which branch from the sides of the bases, and each leg having a foot at its lower free end with a hook facing inwardly that presents a face engaging the underside of a rail and a face engaging the outer edge of such rail; a projection at the back of each foot adapted for engagement by a tool to flex the leg outward to disengage from or engage with a rail; end brackets for the terminal block segments and mounted on said track, each end bracket having an upright strip bearing against the end face of an endmost segment, and a web section including a vaulted central portion that fits between the fingers of the adjacent segment and serrated edges on either side of said central portion which extend beneath the fingers of the adjacent segment and grip the inside surfaces of the flanges; and a headed mounting member between the fingers of a segment for joining the terminal block with a panel.

7. In a terminal block the combination: a channel shaped mounting track having spaced upwardly turned flanges that terminate in outwardly extending generally horizontal rails; and a plurality of individual segments removably mounted on said track that are disposed in side-to-side abutting relation, each segment having a base with a portion that extends downwardly between the flanges of said track and engages both the upper surfaces of the rails and the inner surfaces of the flanges, and also having a pair of spaced slender legs depending from said segment from a level substantially above said rails and that lie to the outside of said flanges, each leg terminating at its lower extremity in a foot having an inwardly turned toe engaging the outer edge and bottom surface of an adjacent rail and an upwardly bent heel extending outwardly from the track to present means for engaging and flexing the leg for the removal of the segment from the track, each segment also having an insulating partition rib extending upwardly from the base and having a first face thereof in the same plane as one face of the base; a boss extending endwardly from a second face of the rib near the upper marginal edge thereof; and a fuse assembly aflixed to said boss and resting upon said seat portion.

8. A segment in accordance with claim 7 wherein said fuse assembly comprises a lower L-shaped conductor member having a terminal arm resting upon said seat portion and a mounting arm attached to the boss, an upper L-shaped conductor member having a mounting arm attached to the boss and a terminal arm extending in the opposite direction from the terminal arm of the lower conductor member, a pair of fuse clips each of which is affixed to respective mounting arms and which extend in References Cited by the Examiner UNITED STATES PATENTS 1,936,963 11/1933 Dutzmann 339198 2,916,159 12/1959 ONeil 248300 2,981,922 4/1961 Van Valkenburg et a1. 339-198 2,983,897 5/1961 Blanchet 339198 3,021,501 2/1962 Blanchet 339198 3,123,425 3/1964 Blanchet 339-198 OTHER REFERENCES Allen-Bradley Bulletin 1492, Snap on Terminal Blocks, page 120, July 1961.

BERNARD A. GILHEANY, Primary Examiner. 

1. IN A TERMINAL BLOCK THE COMBINATION COMPRISING: A CHANNEL-SHAPED MOUNTING TRACK HAVING SPACED UPWARDLY TURNED FLANGES THAT TERMINATE IN OUTWARDLY EXTENDING GENERALLY HORIZONTAL RAILS; AND A PLURALITY OF INDIVIDUAL SEGMENTS OF STIFF INSULATING MATERIAL REMOVABLY MOUNTED ON SAID TRACK AND THAT ARE DISPOSED IN SIDE-TO-SIDE ABUTTING RELATION, EACH OF SAID SEGMENTS HAVING A BASE WITH A TRUNK THAT EXTENDS DOWNWARDLY BETWEEN THE FLANGES OF SAID TRUNK AND ENGAGES BOTH THE UPPER SURFACES OF THE RAILS AND THE INNER SURFACES OF THE FLANGES, EACH BASE ALSO HAVING A PAIR OF SLENDER LEGS THAT LIE TO THE OUTSIDE OF SAID FLANGES AND ARE SPACED FROM SAID TRUNK TO DEFINE A VAULTED SPACE BETWEEN EACH LEG AND SAID TRUNK WITH THE TOP OF SAID VAULTED SPACE AT A LEVEL SUBSTANTIALLY ABOVE SAID RAILS TO PROVIDE LIMITED FLEXIBILITY TO SAID LEGS, EACH LEG TERMINATING AT ITS LOWER EXTREMITY IN A FOOT HAVING AN INWARDLY TURNED TOE ENGAGING THE OUTER EDGE AND BOTTOM SURFACE OF AN ADJACENT RAIL FOR GRASPING THE RAIL, AND EACH LEG ALSO HAVING AN UPWARDLY BENT HEEL EXTENDING OUTWARDLY FROM THE TRACK TO PRESENT MEANS FOR ENGAGEMENT BY A TOOL TO FLEX THE LEG AWAY FROM SAID TRUNK FOR THE REMOVAL OF THE SEGMENT FROM THE TRACK. 